Effect of farming practices on growth and mortality rates in triploid and diploid eastern oysters Crassostrea virginica

Commercial off-bottom aquaculture of the eastern oyster Crassostrea virginica is challenged by repeated summer mortality events that appear to affect triploid oysters disproportionally. Many farmers believe common farming practices, especially when performed during hot months, may increase mortality. The goal this study was investigate how diploid and react stressors imposed farmers: tumbling size grading desiccation prevent biofouling. Triploid were deployed in floating cages at 3 farm sites along US Gulf Mexico coast. In May July, 7 subjected 1 6 stress treatments: levels (18, 24, or 48 h) mixed with 2 (tumbled not tumbled), a never handled, submersed control. growth rate assessed June, August, September. Growth rates both ploidies affected compounding stressors; is, treatments longest period exhibited slower growth. greater response than oysters, increased all extreme compared Based on study, should limit time (particularly triploids) months avoid any reduced resulting from stressor effects.